1. Field of the Invention
The present invention relates in general to the field of information handling system power supply, and more particularly to a system and method for managing information handling system power supply capacity utilization.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
As information handling systems have grown more powerful over time, the infrastructure that supports operation of the information handling systems have had to adapt to increased power consumption. For example, central processor units (CPUs) that perform greater numbers of calculations per time unit typically consume more power than less-powerful counterparts. In addition to the power consumption increase tied to the greater number of calculations, more powerful CPUs also typically produce greater amounts of heat as a byproduct of their operation. The increased thermal energy generally calls for the use of more powerful cooling fans to keep the information handling system within a desired operating range. One approach to address greater infrastructure needs is to support multiple information handling systems within a common chassis that has shared infrastructure. For example, blade servers typically support multiple blades in a common chassis with the blades sharing cooling and power resources under the management of a chassis management controller (CMC). Efficiencies often result when infrastructure is shared, especially where a single hardware device supports multiple information handling systems so that fewer hardware devices are needed and overall cost is reduced. For example, a blade chassis might have three power supplies shared between a dozen blades using a power budget managed by the CMC.
One difficulty that arises when multiple power supplies are used in a system is that some available power is lost when the power load is shared across multiple power supplies. The actual power available to the system is the sum of the power supplied by the individual power supplies corrected for system factors, such as efficiency and system overhead, minus the power lost to the load sharing mechanism, known as the load sharing power loss. In order to prevent any one power supply from exceeding its capacity, information handling systems typically assume a worst case load sharing power loss based on the actual power supplies when setting the system's power budget. For example, a worst case load sharing power loss might reflect extremes of the possible power distribution that covers 99.5% of the entire population of available power supplies. Thus, in actual systems, the actual load sharing power loss is designed to be much lower than the worst case numbers that are assumed to create the power budget. However, using worst case assumptions to generate a power budget typically means that some of the available capacity of the power supplies goes unused. Where the available power supply capacity is close to the expected demand of information handling systems that use the power, the system is typically loaded with more expensive power supplies that have greater capacity or operated with less expensive power supplies at reduced levels that consume less power.